This is also partially affecting me on my series x. Chunk loading does not appear to be slower but the command list takes a good 5-15 seconds to load and the lag in the nether is severe. I have only used the locate biome command but it took a significant amount of time for it to find what I was looking for. It seems this issue is also affecting more powerful devices on other platforms as well.
FRANKTANKSTER
This is also partially affecting me on my series x. Chunk loading does not appear to be slower but the command list takes a good 5-15 seconds to load and the lag in the nether is severe. I have only used the locate biome command but it took a significant amount of time for it to find what I was looking for. It seems this issue is also affecting more powerful devices on other platforms as well.